Bathing installations typically include a heater assembly connected in a recirculating water flow path, with a pump to circulate water through the heater and typically a filter. The heater assembly may include an electrically powered heater element, such as a resistive wire embedded within a heater rod immersed within a heater chamber. With the heater element exposed to the water flow, heater failures due to corrosion can occur.
Exemplary bathing systems with heaters and electronic controllers are disclosed in U.S. Pat. Nos. 6,282,370 and 7,030,343, the entire contents of which are incorporated herein by this reference.